psych analysis - chapter 2

variable

something that varies

constant

something that doesn’t vary

manipulated

• controlled

• changed by researcher

• randomly assigned

measured

observed, recorded

independent variable

• manipulated

• antecedent of interest

• at least two values determined by researcher

  • levels, conditions, treatments, groups

dependent variables

• measured

  • value determined by affect/behavior/response

• outcome of interest

construct validity

the extent to which a test or measurement tool accurately measures the theoretical concept or trait it claims to evaluate

operational definition

how a researcher turns an abstract concept into something measurable

inferential claims

a statement that the evidence or reasons provided support, imply, or lead to a specific conclusion

• frequencies - states the rate or level of one measured variable without comparing it to the other variables or stating a cause

• associations - two variables link, predictable

• causality - this causes that

frequencies (in inferential claims)

states the rate or level of one measured variable without comparing it to the other variables or stating a cause

associations (in inferential claims)

two variables link, predictable

validity

how accurately a method, test, or study measures what it claims to measure

internal validity

the degree of confidence that a study’s results prove a true cause-and effect relationship between variables, rather than being the result of other outside influences

• degree to which study can accurately conclude that independent variable causes dependent variable

external validity

how well the results of a study can apply to other people, settings, times, and real world situations

• degree study accurately generalizes to others

  • sample

  • settings

  • outcomes

  • conditions

criteria for causality (this links to that)

• temporal precedence - a presumed cause must occur BEFORE its effect in time

• covariation - the tendency for 2+ variables to change or vary together in a related way.

• ruling out alternatives

temporal precedence

a presumed cause must occur BEFORE its effect in time

covariation

the tendency for 2+ variables to change or vary together in a related way.

internal validity/external validity trade-off

• internal and external validity tend to be inversely related

  • as control increases, less generalizable to the real world

  • studies that are in the field and reflect real world samples/settings/outcomes/conditions are harder to manipulate